Container handling apparatus



y 1944' I H. EUGANTZER 2,352,949

CONTAINER HANDLING APPARATUS Filed Sept. 11, 1942 3 Sheets-Sheet l INVENTOR Mag/271E anifyer y 1944. H. E. GAVNTZER 2,352,949

CONTAINER HANDLING APPARATUS -Filed Sept. 11, 1942 3 SheetsSheet 2 INVENTOR flbwarcz 62.2??? e? ATTORNEY July 4, 1944.

H. E. GAN' I'ZER CONTAINER HANDLING APPARATUS F iled Sept. 11 1942 s Sheets-Sheet s INVENTOR JfowarcZE -6a?1 7 e7' Y 9 W ATTORNEY E Patented July 4, 1944 UNITED STATES PATENT OFFICE CONTAINER HANDLING APPARATUS Howard E. Gantzer, Kenmore, N. Y.. assignor to Consolidated Packaging Machinery Corporation, a corporation of New York Applicationseptember 11, 1942, Serial No. 457,966 v 10 Claims.

The present invention relates to apparatus for applying closures to containers and, more particularly, relates to the provisionof means for so relating the closures to the containers that the closures will be uniformly loosely applied thereto to permit of some further treatment of the contents of the container before the same is finally sealed.

In the packaging of many commodities such as food products and particularly such as coffee, it is frequently desired to assemble a closure device with 'a container and to leave the closure device in a somewhat loose condition whereby air may be evacuated from the interior of the container or whereby the air may be replaced by some inert gas, and while this condition persists the closure is finally sealed. In one typical packaging system involving the evacuation of a filled container, the

container may comprise a glass jar adaptedto hold a predetermined quantity of coffee to which is applied an ordinary screw cap. There are com-' mercially available capping devices which are adapted to rapidly and eificiently position such caps upon such containers. These commercially available capping devices are relatively large and it is not altogether feasible to enclose the entire device within'a vacuum chamber. It is therefore a normal procedure to employ a standard'form of'capping device and to conduct the capped containers to an evacuating station arranged in the production line beyond the capping device. It is apparent that the containers must not be finally sealed when they are operated upon by the vacuuming device because it is necessary for the interior-of the container to be exposed to the action thereof. Various procedures to this end have been adopted with varying degrees of success. It is possible to adjust the capping device in such manner that it will apply the caps in a loose con-' dition, but such procedure is not entirely satisfactory inasmuch as it is virtually impossible to secure a uniform degree of looseness in each of the successively capped containers. Minor varia tions occur in the containers themselves andin the caps, and a slight misshaping of the threaded portions of one or theother of these elements may result in termination of the capping operation while the cap has yet three 'or four revolutions before final sealing. Other cap and container combinations within the same group may result in such loose threaded relation that the cap may be inadvertently too tightly applied. In

either of these events an imperfect package willbe produced. The ordinary form" of evacuatingapparatus includes a chamber into which'the con- 55 tainers are successively introduced and within which is located additional capping chucks which are caused to rotate when evacuation of the container is complete. The rotation of these additional chucks must be relied upon to efiect final sealing of the containers. In orderto simplify this type of apparatus and to speed the operation thereof, the additional chucks are given a very limited amount of rotation. It is clear therefore that the supply of containers whose caps uniformly need but a small fraction of a revolution for final sealing will lead to increased speed of operation and the production of perfect packages.

Accordingly, it has been found that the best procedure is to apply the caps in the original capping machine to a degree of tightness normally encountered in the final seal. The caps ar then reversely rotated to a'definite extent which experience has taught to be' sufficient to permit evacuation and which is within the limitations of ordinary evacuating apparatus. The reverse ro-' tation may be imparted to the caps by a carefully supervised hand operatiombut the need for-such careful supervision renders this procedure i'mpracticaL- It has also been'proposed toso construct the capping machine as to tightly apply the caps by rotation of the capping chucks in one direction and then to impart to the chucks a predetermined rotation in the opposite direction This lat-' whereby to uniformly loosen the caps. ter procedure is entirely satisfactory from an operational standpoint but'it involves the necessity for construction of a special capping machine;

It is therefore an" object of the present invention to provide a simple apparatus in the natureof an attachment which may be associated with a capping machine or with the evacuating apparatus or withthe conveying and transferring ap-'- to provide an attachment of the type set forth which may be simply adjusted to impart varying degrees of reverse rotation to the capsof tightly capped containers upon which it operates.

It is a further object of the present invention to provide an attachment of the type set forth which is exceedingly simple in construction, reliable in operation, and unlikely to need repair.-

Other and further objectswill become more ap-- parent upon a consideration of the following detailed description taken in conjunction with the drawings forming a part of the specification. In the drawings wherein similar characters of reference indicate similar parts throughout the several views, there is illustrated a preferred, but obviously not necessarily the only, embodiment of the present invention.

Referring to the drawings in detail:

Fig. 1 is an elevation of a capping machine embodying the present invention;

Fig. 2 is a horizontal cross-sectional view of the same taken along the line 2-2 (if-Fig.1;

Fig. 3 is an enlarged detailed view similar 'to Fig. 2 but showing only a portion ofthe' cappin'g' machine and the attachmentthereto embodying the present invention;

Fig. 4 is a view similar to Fig 3=showing the parts in a different position;

Fig. 5 is an elevational view taken from theline -5 in Fig. 3;

.Fig, 6- isa section .along 'the irregular line -6W6 Fig. .5- isy-a sectionelim 10m;- the-Jinela-l- 8 is a horizontal .-seetiontaken along "the line 18-8-- r-Fiam Figs. 9;.10 and 11 are detailed views showing the-operatieuwofthe apparatus of the-present inventionmand- 7 Fig.1 1-2-shows--a .inedifiedform of friction-mg devicewhich may-be employed;

Each of thesectional views-has been taken in the (direction ;of the" arrows: associated with :the respective section--lines:.-'

Referring nowwto Fig. l;-there ris ehownacapping machine of commercialif ormmowhich the present invention may conveniently-be :applied. In general, this'machine' comprises -.a base l containing theneces'sary motors and drive apparatus and upon'which is supported a "capping table *2. Containers are" conducted mitt-recapping table--12 by an: intake -"conveyor. indicated generally at 1 4 and upon which the containersare advanced by themovement'of-jconveyor chains I-B iii the-direction of'-thearrowlfl'into engagement with a star-shaped feeding-wheel 20, T' rotatably' "supported upon the table flf lheieeding wheellil has notches 21" formed therein and "within which the containers are adapted to seated. It-will be understood that thenotches 22are' suitably shaped'for reception "of the particular container being operated upon Above the'feeding wheel 20 and 'drivenfo'r rotation "therewith isf-awabpositioning whet- :114 towhich caps are red (by the-discharge" apparatus oi suitable" cap-sorting means not f shown'here'im It will be-understood that the caps arofiurnishedtothe wheel 2'4 in" such manner as to be conducted thereby in positions vertically aligned with -eacheontaine'r seated within a' notch Z2 of thefee'dingwheelifil Reference is here made 'to ratenczansss granted May 13, I941, td Gantzer which thereis a dz'etailed showing of -one"ma nn'er 'inwhich the caps may be associated with the containers and in which-the following briefly described? apparatus is shown in co'nside'rablyg'reater detail.

Y The containers and the caps aligned therewith are carried 0 the c ap- 'applying station through the rotation-bf the wliels'" 2 8 ar-id 24. =In this station'gthe' containers are transferred from the wheel 'tda star'wheel 26 -which includes suitable automatically-operable gripping .l'aws 28 {for engaging -the containers and holding them meantime, the caps carried by the wheel 24 are picked up by cap-applying chucks 30 carried within the capping turret 32. The chucks 30 are arranged for suitable motions necessary to pick the caps from the wheel 24 and to lower them into engagement with the respective containers held by the jaws 28 of the wheel 26. When the caps have been thus lowered into engagement with the containers, the chucks 30 are rotated in proper direction to screw the caps upon the containers. Any suitable system of control of the chucks 30 may be employed and it will be clearly "understood; thatrany such system will result in theapplication of the caps to a suitable degree eftightnessneces'sary for proper sealing of the -container.- -Reference is here made to U. S. Patent l','7-54,461granted April 15, 1930, to Cundall antito :UzS. Patent 1,773,960 granted August 26,

1930, to Cundall for illustrations of suitable chuck control systems. -When the 'cappingoperation is completa-the chucks-30 are raised iromengagement with-the caps and the capped containers are ready-for discharge from themachine. Discharge maybe effected by release of'gripping-engagement of the laws 28- w-i-th the containers, as shown in said Patent 1,"l54,461"er inU. S. Patent 2,285-26-7 granted June 2, 1942, to Gantzer, and impact of thecontainers with a suitable curved-guide positioned upon the capping table -|-2.- :A- rotary dis-' charge wheel 36 maybe provided for engaging each successively'presented container and swinging it around the curved path defined by the guide 34 into adischarge chute 38. The discharge chute 38- may carrythecontainers to the next succeeding station by any suitable means not shownp- I The apparatus of the present invention maybe attached "to the "commercial capping machine above briefly described "in such" position as "to" operate upon the containers"immediatelythat the: caps have been tightly 'appliedtheretof Thus; a convenient location is thatillustrated in the drawings wherein this apparatus is positioned'i-n thepath ofthe containers as they'move from the star wheel 26 intothe "curved path defined by the guide 34; At this particular point, the containers are 'still' gripped by the jaws '2'8, and they will remain so'gripped until the discharge wheel 36 isbrought into contact therewith'for the purpose said Patents 1354.461or-"2,285,267. the

interval of time existing between the release of the capping'chuck' from the tightly applied cap to the'r'elease of the container from the jaws 28 is availed of in the "present invention to reversely rotate the caps to a uniform predetermined extent suflicientto permit subsequent evacuation of each container;

To this end, abra cket 40 is secured to the capping table "I 2 and a vertical bore is formed therein adapted to receive 'a'post'42. The post 42 is pro- Vided with a V- shaped groove 44 (see Fig. 6) adapted to receive the end of a set screw '46 threaded into the bracket 40. The post 42 may thus be vertically adjusted within the bracket 40 andsecure'd in adjusted position by tightening of the set screw -46. The set screw 46 also serves to hold the post' l'tagainst any rotation about its own l'ongitudinalaxis. At its upper end, the post 42- receives a hub 48 intowhich' is threaded a pair ofset screws 50 (see- Fig. 3-) adapted toisecure the hub in a rotated positionof adjustment relative-to the post 42. An arm 52 and an extension thereof 54 are secured to the hub 48 and they may be adjusta'bly positioned across the path of the containers carried by the star wheel 26 (see Fig. 3). From the construction just described, it will be apparent that the arm 52 and its extension 54 may be positioned'in horizontal and vertical planes suitable for operationupon the particular containers being handled by the capping machine. I

"At the inner end of the extension 54, there-is mounted a strap 56 freely pivoted upon a stud 58 carried by the extension 54. The strap 56 carries at its free end a roller 68- which is freely rotatable upon a stud 62 secured to the strap 56.- The roller 68 extends downwardly from the strap 56 and it is intended that the arm 52 be so vertically positioned 'that'the roller 68 will engage the peripheral portion of the caps secured to containers passing through this device. A proper position of adjustment of the parts'to this end is illustrated in Fig. 6.

At its outer end, the extension 54 has freely pivoted thereto upon a stud 64 a lever 86 extending in generally parallel relationship with the strap 56. The lever 66 hasform'ed thereon a perforated ear 68 which loosely receives a reduced cylindrical extension 18 of a link 12 freely pivoted at |4 at'its other end to the strap 56. The extension 18 is preferably threaded for the reception of lock nuts 16 between which and the perforated ear 68 is confined a compression spring 18. The compression spring 18 thus tends to draw the lever 66 and strap '56 toward one another. The extent of movement of the lever'6'6 and strap 56 toward one another is limited by abutment of the ear 68 against a shoulder 88 formed upon the link 12. The shoulder 88 is formed in such position as topermit the lever 66 and strap '56 to swin toward oneanother into a position wherein the distance therebetween issomewhat less than the diametral width of the caps upon the containers.

The strap 56 has formed thereon a stud 82 adapted to abut with a notch 84 formed on the extension 54. Similarly, the lever 66 has formed thereon a stud 86 adapted to abut with a notch 88, also formed upon the extension '54. The spacing' between the notches 84 and 88 and the positioning of the studs 82 and 86 are such that abutment will not occur between both of the studs 82 and 86 and their respective notches when the lever '66 and strap 56 are moved toward one another to the greatest extent permitted by the shoulder 88. Thus, the lever 66 and strap 56 are yieldably urged toward one another by the sprin 18 and they are freely fioatable'about their respective pivots 58 and 64 within the limitations of spacing between the studs 82, 86 and their respective notches 84, 88.

The lever 66 is provided with some suitable form of relatively stationary friction device for engagement with the periphery a rim of a cap carried by a container. This friction device is preferably so positioned as to engage the cap in non-slipping relation in a position generally diametrically opposite the engagement therewith of the roller 68. The friction device may comprise a block 61 of rubber or leather or metal having a knurled surface secured to the lever 66 as own n F 12. In its preferred form, the friction device comprises a single, relatively sharp tooth which is adapted to engage the knurls formed upon the rim of one standard form of screw cap. It will be understood that this par- 75 ticular friction device is suitable for that particular typeof cap-which is chosenfor illustration herein and that other forms of friction devices such as those suggested above may be adopted for different forms of caps.

As shown in Fig. 6, a container 98 is engaged between the'gripping jaws 28 of the starwheel 26 and it has tightly screwed'thereon a. cap 92 which is formed with a knurled periphery of familiar form. As stated above, the roller 68 engages one portion of this knurled periphery and the friction device upon the lever 66 engages the substantially diametrically opposite portion thereof The adjustment of the device is such that the spacing between the roller 68 and the friction device of the lever 66 is somewhat less than the diametral width of the cap 92, and as the cap is broughtbetweenthese elements they are forced apartthereby against the force of the spring". The friction device is relatively stationary, and since the container is gripped by the jaws 28 in its motion past this stationary friction device, the tendency will be for'the friction device tohold the cap and cause it to rotate about the point of engagement between the cap and the'friction device. Continued movement of the container will thus result in a relative rotation of the cap to the container in a direction opposite 'to that in which the container is moving. Assuming that the cap has been applied to the container by a clockwise rotation of the capping chucks 38. movement of the capped container past the friction device in the manner above described will result in a relatively counterclockwise rotation of the cap whereby to loosen it.

The action above described is generally a'rolling of the cap upon the friction device. Thus, if the friction'device is a block of rubber or other material presenting an extensive surface, the rim of the cap will roll thereupon and the cap itself will rotate relative to the container.

In the form of the device chosen for illustration with the particular cap 92, the friction device 'comprlses'a blade 94 extending from the lever 66 inwardly toward the roller 69. As shown in Figs. '7 and 8 the blade 94 is carried beneath the lever 66 within a channel 96 formed in a clamping plate 98 held to t e lever 66 by screws I88. A suitable number of spacing blocks 182 similar in cross-section to that of the body of the blade 94 is positioned within the channel 96 and they are so proportioned as together with the blade 94 to fill this channel. For a purpose to be hereinafter described, the blade 94 may be moved into any of the positions occupied by the spacing blocks I82 and the blocks will, of course, be suitably rearranged.

While the operation of the device has been generally described as the detailed description progressed, it will be briefly reviewed with particular reference to Figs. 9, 10 and 11. In Fig. 9, the cap 92 has advanced to such position as to be brought into engagement between the roller .68 and blades 94. Further movement of the cap in the direction of arrow I84 will force the roller 68 and blade 94 apart against the spring 18 and will result in the blade 94 holding a single point in the periphery of the cap against rotation. Inasmuch as the. container with which the cap'is ass scciated is still held by the'jaws 28 a relatively counterclockwise rotation will occur between t e cap 92 and itsassociated. container. In Fig. 10,,

the cap has advanced to such position that the roller 68 and the blade 94 are diametrically op-- posite one another. In Fig. 11, the cap. has pro-.

seeded as such Lpos'ition; thatlth'e and blade M have"swurrg toward'iorre another to the extent permitted by 'thetshoulderzsll onitheliink' 12. It will loo-apparent that when thislatterposition isreached no further iforcewillbeeiterted upon thecap betweenthe rolle'rifi iarrd blade by the .action of the spring: 18'.'""- 'Ih'e' relative counterclockwise rotation of the-"cap andrfitcontamer will th'encease. I

The-action of the blade is:very similar'to the action of an extensiverollingisurfaceas de scribed above. The blade engages the periphery (if the cap as shown in Fig; 9,:ren'aotsegamst the spring '18' as shown. in Fig." ;"and advances under pressure-of the spring .18 asshownin'i ig. 11'. Thus, in'efife'ct, the single blade '94 is equivalent to anextended surface. It will be recalled that "thelever'fi'fi and 'the strap 56 may approach one another ion-1y to the extent permitted by abutment of theear afl' with the shoulder 80. Thus in the-event-it-is-desired to impart a greater orlesse'ramount-of our-item clockwise movement to-the' cap-of a container -the bl-ade94 nray be moved lengthwise of itselr-to vary the distance between its edge" and the-periphery of the roller 60.- When theedge of'the blade 9 4'is close'to the roller 60 the cap-willbe engaged earlier and will remainen'gaged longer than it will-when the blade is farther awe5m- The -adjustment of the blade 94 may be-efiected by temporarily loosening the screws-l-0-l whereupon the blade 94 may be moved lengthwise of itself-to desired position. -A-n example of a tposi tion in which the blade is relatively closer to the roller 60 is shown in broken lines in Fig. 8 at 84c. it will be understood that the lengthwise adjustment of the-blade 94 aforesaid willresultina change in the angle of approach of the edge of the blade 94 to the periphery of a cap. Such change in the angle of approach may not cause any diiiiculty, particularly in the event caps with knurled peripheries are involved. Howeveryin other instances it may be advisable in order to insure proper gripping action to make a cornpensatory adjustment of the angle of approach when a lengthwise adjustment of the blade has been made. To this end the blade 94 may be moved to one or the other of the positions occupied by the spacer blocks I02 at the same time that a lengthwise adjustment of the bladeis made. An example of such a movement is illustrated in Fig. 8 whereinthe'blade 94 maybe moved to a position shown in broken lines at 941). In' this position the blade has been moved lengthwise of itself whereby to bring its edge closer to the roller 60 than it is in the position shown in full lines. The blade hasalso been moved into a position formerly occupied by one of the spacer blocks I02 closer to the pivot 64 of the lever 66 to approximately compensate for the change in angle of approach resulting from the lengthwise movement of the blade. 1

From the above detailed description, it will be apparent that there is provided a structural embcdiment capable of accomplishing the objects of the present invention. This structure has been shown as an attachment applied to a capping machine. It is obvious that the attachment may be applied at any suitable point within a production line, the only requirement being that the container body be held against rotation about the point of engagement between the friction device and the periphery of the cap for a suitable period of time to permit of the operation of this attachment. Modifications. and V variations will c rome :occur.::to ithosezskilled in the; art,'.and itissthe intention thatfthe above detailed description-shall be taken in an illustrative rather than a limiting sense'whereby any such modifications and variationsialling within the scope of the appended claims are intended to be covered thereby.

;l. In apparatus for handlingcontainers having screw caps tightly applied thereto, -the--combination of cap-unscrewing means; and means for moving capped containers throughja :predetere mined path of travel relative to said capu-nscrewing means; said cap-unscrewing means being positioned in the path of travel of the-caps carried by said containersand comprising, friction means adapted to engage the rim of a cap in-non-slipping relation, anti-friction means; and means to urge said last two means, respectively, into engagement with generally diametrically opposed regions of the rim of each cap as each of said caps passes between said friction means and said'anti-friction means during movement of each container through adefinite portion of said path of travel to cause a predetermined amount of rotation of each of said caps relative to its associated container;

2. In apparatus for handling containers having screw caps tightly applied thereto, the combination of cap-unscrewing means; and means for moving capped containers through a predetermined path of travel relative to said capunscrewing means; said cap-unscrewing means being positioned in the path of travel of the caps carried by said'containers and comprising, friction means adapted to engage the rim of a'cap in non-slipping relation, anti-friction means spaced from said friction means in a direction substantially transverse of the pathof travel-of said caps, means to urge said friction means and said anti-friction means, respectively, intoengagernent withgenerally diametrically opposed regions of the rim of each cap as each ofsaid caps passes between said friction means and said anti-friction means during movement of e'ach container through a definite portion of said'path of travel to cause a. predetermined amount: of rotation of each of said caps relative toitsassociated container, and means for varying the spacingbetween said friction means and said anti-friction means for changing the predetermined amount of rotation of each of said caps. 3. In'apparatus for handling containers having screw caps tightly applied thereto, the combination of cap-unscrewing means; and meansfor moving capped containers through a predetermined path of travel relative to said capunscrewing means; said cap-unscrewing means being positioned in'the path of travel of the caps carried by said containers and comprising, a blade having an edge located in the pathof travel of said caps, and means to urge the edge of said blade into non-slipping engagement with the rim of each cap during movement of each cap through.

a definite portion of said path of travel to cause a predetermined amount of rotation of each .of said caps relative to its associated-container 4. In apparatus for handling containers having screw caps tightly applied thereto, the combiner-- tion of cap-unscrewing means; and means. for moving capped containers through a-predetermined path of travel relative to said "capunscrewing means; said cap-unscrewing-meansbeing positioned in the path of travel of the caps carried by said containers and compr'ising,--a blade having an edge located in'the path-of travel of said caps, anti-friction means, and means to urge the edge of said blade and said anti-friction means, respectively, into engagement with generally diametrically opposed regions of the rim of each cap as each of said caps passes between said edge of said blade and said anti-friction means during movement of each container through a. definite portion of said path of travel to cause a predetermined amount of rotation of each of said caps relative to its associated container.

5. Apparatus for uniformly loosening screw caps tightly applied to containers, comprising means for moving a container having a cap thereon through a predetermined path of travel,

a blade having an edge located in said path of travel in such position as to engage in non-slipping relation the rim of said cap during movement of said cap through a definite portion of said path, and means for adjusting the position of said blade with respect to the path of the center of said cap whereby to vary the amount of rotation imparted to said cap.

6. Apparatus for uniformly loosening screw caps tightly applied to containers, comprising means for moving a container having a cap thereon through a predetermined path of travel, a blade having an edge located in said path of travel in such position as to engage in non-slipping relation the rim of said cap during movement of said cap through a definite portion of said path, and means for holding said container to insure rotation of th cap with respect thereto.

7. Apparatus for uniformly loosening screw caps tightly applied to containers, comprising means for moving a container having a cap thereon through a predetermined path of travel, a blade having an edge located in said pathof travel in such position as to engage in non-slipping relation the rim of said cap during movement of said cap through a definite portion of said path, means for holding said container to insure rotation of the cap with respect thereto, and means for adjusting the position of said blade with respect to the path of the center of said cap whereby to vary the amount of rotation imparted to said cap.

8. Apparatus for uniformly loosening screw caps tightly applied to containers, comprising means for moving a series of containers having caps thereon through a predetermined path of travel, a first lever, a blade carried by said lever and having an edge located within said path in such position as to engage in non-slipping rela tion the rim of each cap moving through a definite portion of said path, a second lever, anti friction means carried by said second lever in such position as to engage the rim of each cap in a region generally diametrically opposite the point of engagement between said rim and said blade, spring means yieldably urging said blade and said anti-friction meansinto tight engagement with the rim of each cap during movement of said cap through said definite portion of said path, and means for holding said containers to insure rotation of the caps with respect thereto.

9. Apparatus for uniformly loosening screw caps tightly applied to containers, comprising means for moving a series of containers having caps thereon through a predetermined path of travel, a first lever, a blade carried by said lever and having an edge located within said path in such position as to engage in non-slipping relation the rim of each cap moving through a definite portion of said path, a second lever, antifriction means carried by said second lever in such position as to engage the rim of each cap in a region generally diametrically opposite the point of engagement between said rim" and said blade, spring means yieldably urging said blade and said anti-friction means into tight engagement with the rim of each cap during movement of each cap through said definite portion of said path, means for holding said containers against rotation to insure rotation of the caps with respect thereto, and means for varying the spacing between the edge of said blade and said antifriction means to change the amount of rotation imparted to said caps.

10. Apparatus for uniformly unscrewing screw caps tightly applied to containers, comprising means for moving a series of containers having caps thereon through a predetermined path of travel, a first lever, a blade carried by said lever and having an edge located within said path in such position as to engage the rim of each cap movingthrough a definite portion of said path, a second lever, anti-friction means carried by said second lever in such position as to engage the rim of each cap in a region generally diametrically opposite the point of engagement between said rim and said blade, spring means yieldably urging said first and second levers toward one another into positions in which said blade edge and said anti-friction means are spaced apart a distance less than the diameter of said caps, and means connecting said first and second levers for joint pivotal movement independent of said spring means whereby upon engagement by the rim of a cap with either said blade or said anti-friction means said first and second levers may be shifted jointly to bring said blade and said anti-friction means into simultaneous engagement with the rim of said cap and upon continued movement of said cap between said blade and said anti-friction means said first and second levers will be moved apart against said spring means, said spring means thereupon acting to press said blade into nonslipping engagement with the rim of said cap.

HOWARD E. GANTZER. 

